In the structure of an electroluminescence (EL) lamp, as shown in FIG. 1, generally two sheets of moisture trapping films (2) hold between them a transparent conductive film (3), a luminescent layer (4) and an aluminum electrode (5) to protect the luminescent layer which is easily affected by water. Previously known moisture trapping films for this purpose are those composed of a water absorbing layer of nylon-6 laminated with an adhesive layer of nylon-12.
In addition to them, there have been moisture trapping films which employ hot-melt adhesives for the adhesive layer. These, however, are always designed to be laminated at a higher temperature between 100.degree. and 200.degree. C., and at room temperature the adhesive has no tackiness.
In the case of using such a moisture trapping film having no tackiness at room temperature, the impact at the stamping readily caused peeling of the moisture trapping film and reduced the yield. This has been a great problem particularly for a large size EL lamp.
Furthermore, when an EL lamp was bent to be used, conventional adhesives caused peeling and provided the lamp with an inferior appearance.
On the other hand, for the most outer layer of moistureproof film (1) also an adhesive of the hot-melt type was used, and the lamination was carried out at a temperature between 100.degree. and 150.degree. C. The higher temperature process of adhesion between the moisture trapping layer and the moistureproof film provided the life of the EL lamp with a markedly poor effect.